Grease trap



Aug. 28, 1945. v C, ARNDT n 2,383,436-

` GREASE TRAP Filed Aug. 20, 1942 2 Sheets-Sheet 1 Charles Arnd]` A Trae/Vey. f g

Aug. 2s, 1945. c. ARNDT 2,383,436'

GREASE TRAP Filed Aug. 20, 1942 2 Sheets-Sheet 2 [NMEA/foe Charles ArndT y f7-Tm A Trae/Vgn Patented Aug. 28, 1945 Charles Arndt', South Pasadena, Calif. y ApplioatonfAugustZO, 1942, Serial No. 455,447 i 9 Claims.

This invention. relates. to grease traps of the general character commonly employed to.'v receive.

the waste waters .fromi plumbing fixtures; such' as sinks` and the like, fonthe: purpose of inten. cepting grease and otherlimiter-than.-waterI sui` stanceswhich would` otherwise tend to: accumulate in conduits= leading therefrom to themain sewage disposal line.

Grease traps of thetype contemplated herein embody essentially a .chamber through which. the waste water is conductedli at a suiiiciently'reduced rate of flow to permit the lighter substances to rise to the-surfaceof the chamber where they are accumulated for subsequentremoval, an outletl for the cleared water to the sewagey system' being provided whichy is. connected to thebottom of'the trap. v

In some communities it is required, that such traps be tightly sealed to preclude emission of` noxious gases emanating.. from the accumulated detritus, and to prevent overow or leakageof any of the Wastewater-in the event that the-oute `let or any conduit leading therefromshould become clogged. 'It will' be readily appreciated that with the topseal'ed, such a device can be rendered completely ineective should the waste water contain an excessive amount of air or other gas, which, rising in the trap, would soon displacethe liquid aswellf as the collected grease.

Moreover, if it is impossibletovent the outlet, a partial vacuum, created inthe outlet conduit, will have a siphonic eiect upon the fluid in the trap. WhenI this occurs, regardless of thev form diiiiculties mentioned incorporating a bypass between the. top'of the inner chamber and the out.--

let Whichunder normal fluid conditions, is-.closed by thewaste water to the passage of sewer gases into. the trap, but which, upon the lowering of the uid level incident to siphonic action of the sewagesystem or due topressure of accumulated gases, is` effective to break the Siphon as well as; prevent the accumulatiom of an excessive volume` 55r-` of gastending to impair theY efficiency of the device; i

Anotherv object is tof provide, a flexible: iiuidf tight connection between the-body of. theitrap andy 2 the iixture servicedfby thevformer'soas-.tocom pensate for sagging.'l of.' theA sink plug or. lateral. shifting. off the plumbingy withfwhich the deviceis associated in use.

Another object is `to provide a'. trap suitable'y for construction of vitreous china. or any other:

material adapted; to withstand. the. temperature and chemicals carriediby-luidsfor theseparation ofwhich it is employed, embodying a novel arrangement of baflles within thefbodyof` the-dei vice operable to retard and spread. the flow of f the trap, ncombinationwith thestructural in-l f vent; l

Fig. 4 isa broken sectional View: off'tlie inletl dependent inlet and. outlet. fittings. adapted for connection, intercl'iangeable,y with either of. said openings, .to facilita-te installation.. of, the'device in restricted areas...

Another object.. is to. providev a. novel. form` of clamping device by which. the` cover of. the trap may.- be quickly-Rand. easily. secured, inv position; and. where. necessary... sealed to prevent escape of gases or overflowof the liquids. directed thereinto. Y

Other objects 'andcorresponding advantages, such for exampleas vfacility, in cleaningthetrap l chamber, simplicity o f construction,.andeconomy of manufacture, will. be apparent to. tl1oseo;f..skil1z in. the art upon an examination of. the following. description, read inthe light of the accompanying drawings, inwhich:

Fig. 1 is a plan view of the trap comprising onev embodiment of my invention with the top cover removed, showing the interior construction and'v the relative disposition ofthe bailles;

Fig. 2 is a sectional View of` the device taken -l on lines 2``2 of Fig, V1`, illustratingparticularlythe vent pipe extending between the upper part` of the body of the trapand the outlet;

Fig. 3 is a transverse sectional-view, taken on' lines 3---3ofL Fig. 14 throughthe outlet pipe: and

pipe and ofthe means by which itis exibly confI nected to the body of.` the trap.

Fig. 5` is` a'longitudinal sectional View through. a` trap comprising a modication; ofimy. invention;-

vitreouschinaor glazed pottery. The trap, rec-l tangularin plan'gomprises side walls 6 and end vwalls 'I and 8 and bottom 9. 'I'he inner sides of the upper edges of the walls of the trap are cut away to form a ledge 21 for the support of a cover plate 28. pressible material such as rubber or the like is interposed between cover 28 and ledge 21. A lug 38 projects from the outer surface of the trap -adjacent each of the corners, for the pivotal support of one end of a clamping bar 3| adapted to be swung over the upper edge of the trap so as to overhang the cover. The upper surface of cover 28 is recessed in the plane of movement of the respective bars 3| as at 32 to accommodate the free ends of the latter which are bent to decline into the recesses 32 when the bars are arranged in clamping position. A thumb screw 33, threaded through the free end of each bar 3| atright angles thereto, is adapted to be Aturned into engagement with the side of the recess to urge the cover firmly onto gasket 29 and thus assure uid-tight seal of the upper part of the trap while permitting facile removal of the cover for periodic cleaning of the interior'of the trap chambers, about to be described.

A partition I8, extending between end walls l and 8, divides the trap longitudinally into a pair of trap chambers I| and I2 which are communicated with one another over the top of partition I for the passage of gaseous substances separated from the waste waters, as will appear. The lower corner of partition I0 adjacent end wal1 isdiagonally cut away as at I3 to form an opening for the flow of the waste water'from one trap chamber to the other. It will be observed that as the width of opening I3 gradually diminishes toward its upper edge, water owing from one chamber to the other .through the opening will be drawn from closely adjacent the bottom of the trap. The bottom 9 in chamber II at the opposite end of the trap is inclined toward the adjacent end wall 8 in which is provided an inlet opening I4. The edge of end wall 8 encircling inlet opening I 4 is recessed as at I5 to form an annular clamping bead I6. In use, the trap is disposed at a level below the sink or other fixture from which the grease-laden waters are to be carried by a drain pipe I'I connected to the sink plug (not shown). If end wall 8 of the trap is composed of metal or the like, opening I4 may be threaded and any of several common forms of fittings employed to effect a connection between pipe |'I and the trap. Where such a rigid connection is employed however, any shifting of the fixture, trap and intermediate plumbing will invariably break the solder connection between the sink plug and drain pipe I'I. Fig. 4 illustrates a novel form of slip joint connection particularly adapted for use in conjunction with the trap composed of frangible material unsuitable for a threaded connection. To this end a tubular member I8 having a polished surface is threaded on the end of pipe Il. Eri-circling the tubular member I 8 is a spud I9 having an Oblique A gasket 29 of suitable comflange 2U of an outside diameter only slightly less than the diameter of the opening through bead I8, whereby it may be inserted into the opening for disposition in recess I5 behind the bead. A rubber gasket 2|, encircling spud I9 adjacent the oblique flange 28, is formed with dual annular flanges 22 and 23, corresponding in contour and angular relationship with the inner and outer surfaces of bead I 6, with opposite sides of which the respective gasket flanges engage. Aclamping nut, 24 ,threadedl on spud I9 against the outer flange 23 of gasket 2| is operable to draw the spud flange 20 against the complementary inner flange 22 of the gasket so as to compress the gasket 2| and form a fluid tight flexible seal between spud and the trap. A packing nut 25 is threaded on the rearward end of spud I9 to compress a rubber ring gasket 26 against the end of spud I9 and assure a fluidtight but slidable connection between the spud and tubular member I8. It will thus be seen that any sagging of the fixture or drain pipe I1 will be absorbed by the gasket 2| or ring 28 or be compensated by the axial movement of the tubular member I8 in Spud I9.

Integral with the partition I0 and respective side walls 6 are a pair of transverse baffle plates 34 which are preferably equi-spaced between the end walls 'I .and 8 and are elevated with respect'to the bottom of the trap. The upper edge of each baffle plate 34 is disposed below the intended fluid level of the trap to permit the lgrease and other debris, rising through the uid to the tcp of either of the `trap chambers II and I2, to distribute itself evenly throughout the latter.

A pair of dams 35 integral with bottom of the trap extend from each side of partition I8 in the respective trap chambers. In each chamber the dams 35 are equi-spaced from opposite sides of the bafiie plate 34, as indicated in Fig. 1. Each dam is preferably of the length equal to approximately three-fourths the-distance between partition III and the opposed side wall 6 and of a height suflicient to extend slightly above the lower edge of the baffle plates 34.

It will be understoodl that While I have described the partition I 3, bafiie plates 34 and dams 35 is being integral with the body of the trap, these parts may be structurally independent or integral with one another but separate from bottom 9 and the side walls B to permit their removal to facilitate cleaning. An outlet opening in the lower portion of end wall 8 comprising the end of trap chamber II extends the width of the chamber I I. lA pair of converging walls 38 project from the side edges of the opening to form with a generally-triangular extension 31 ofr the bottom of the trap, an outlet chamber 38. A tubular outlet conduit 39 integral with the walls 36 of outlet chamber 38 extends vertically upward and terminatesin a bell end 48 flush with the upper edge of the trap for connection in a suitable manner of a short pipe 4| to which a clean out plug, cap or vent pipe may be threaded. A side opening 42 is formed in the tubular member in the plane of the fluid level desired in the trap chamber and is provided with an integral bell fitting 43 into which a sewage disposal pipe (not shown) may be connected by the use of cement or the like.

Laterally of the outlet 39 a vent tubev 44 is provided which in the embodiment of the trap of Figs. 1-4, is integral with the outlet conduit andi body; of the:` trap. 'Ilube 44' is-r communi;- cateds at: its,r lowerzend: withav thetsideof theoutlett slightly' below the: lateral. drainvopeningi 42; as atl45., The`upperr-endf of'. tube Mi terminates flushwithi thei4 topor the: wallsy ofgxthetrap and isi-connected@ to: the. outlet: 39: and adjacent' end wall@ 81 byC af web-,46g in which an annular. channel-.41' encircling:v the: upper end of tube 44 is formed.-v A passage 448,-

provided through web 46- and? wall 8 whichs connectschannel 45t with the interior:k of: the: trainattheV upper part of adjacent'.endlwalll-` A short normally-capped pipe. 4&9- is fltted-V into' the: enlarged` upper part of the bore of channel 41 through theboreiofl which. the channel: and: tubef are communicated.

The operation of theztrap'in separatinggrease the Waste water `from the trap chamber-'to'anlex.;`

and other lightenthan-Water particles; flowing withithe wastewater-from the: drain towhich the traspfisnoonnectedlis briefly described as. follows: Water'passingrf'rom drain-AV pipe l'lenters the trap its-i` rate of flowy immediately decreases due toi the. greater cross sectional area of the trap chamber II- with respectyto-the drain pipe. Accordingly the-lighter particles will inmediately tend to-separate and-begin tez-rise to the surface of. the liquidy in Lthe trap.- l 'Bhe water isfprevented from-forming a streambet-Ween drain pipe l-land opening: I-3 bythe' damsl3i=andlbafe plate34. The waterV from: the inletstrikesf the-dam 35l disposed' between.- inlet and"v baille 34,v which causes the flowtospread throughout; thewidth=` of thetrap. Some.- offn thewater `iiowslover, theidam whilev that whichiis-directed-laterally toward' the side wall is permitted; tol-flow aroundfthe end of the dam.f The weten is-thenfcompelledz.to-'flow under baffle 34 whichtunctions: to further distribute the: Waste' water;- throughout the-width of trapy chamber ll, thus assuringuniformA retardation oft the.x flow. Water' passing; under, th'e baille-plate I 34 in cham ben H adjacent partition lllfis* compelled to rise in order tofow-ove-r theadjacentdst-m35.` `Asfthe opening- |3 in? partition; Ill isat-L the bottom of` the trap, this-water will, immediately after passing, over alledem-35;, return'to' adjacent the bottom Stof the trepa-so asnot. tovdisturb the accumula-- tiensf ot greasef on the surface; Water flowingr adjacentltlre outer side walllof the chamber Irl moves under-1 baille 34 in awide arc to, opening I3;` It will thus be seen that baille plate 34 and openingv- I3 confinethegrease-laden water tothe bottom, ofT the: trap. so. as,not.to disturb-*the greasy i substances theretofore collected. In; the opposite.

trap chamber l2 thewater issimiIa-rly compelled toflow either over, oraroundtherst dam 35and. thence .under the baille plate 34, The part.. of th'e flowy passing.. near Vpartition l0. rises over. the dam 35.at the .opposite side ot the baillawhich serves to increase the. distance travelled as'well as, to.. slow. down the. rate of the ow'by distributing. the now. uniformly throughout the width of. chambers H. and l2.. Ilhe-converging` walls 36I of, the outlet chamberx 38- draw Water. from-the entire lower porltion of trap chamber Il intothe4 outlet chamber soiaslto further obviate any tendency toward the formation of a stream or current fromv inlet I4 tothe outlet.A Itiwlbe observed thatdue to the arrangementof` dams-35 and baille 34 th'e greatest volumeof theY flow from the inlet to the outlet follows an-.undulated patlr close to thebottomof the: trap While the rest of the liquid moving to the outlet flows in a wide arc whichalordsl ample time, with-,thepretarded-rate of flow, for the greasy substancesto separate'.

The fluidflevel-within theftrap will-be normally determlnediby'theoutlet from which the cleared tent which would tend to agitate the:accumula-` tions of grease or permit any part. of. the, same-.to be drawn off through-the outlet conduit 39.` It" will also be observed that air carried with the wastewater-will; with th'e grease,gtend;torisein. the trap and accumulate under-the sealed?z cover- 28; In-the absenceofa suitable-vent, an excessive amount Vof air carriedjinto the trap-by the: waste` water and accumulating` in the upper part of the trap, will-soon displace enough of the-Water-` to seriously interfere vwith continued efficient operation. Any/tendency toward the' development, of? this condition during the'useand operation ofthe` present-device is obviated: bythe communi-- cation' between thel upper" part of the` trap and the outlet* conduit 39v ltlorough'the venty tube 44; The-volume of; air or' other. gases thus-accumulat-m i ing wouldy be limited ,to the volumetric capacity of the trap above the-point of connection :'between tube 44 and outletucondu-it 39. As the--fowfromthe. inlet'- to: the outletis closely-v conflnedto the bottom of. the trap-byfthe-baille-plates 34-'there Willbe at sufficient depth-of fluid' in thetrap'even when loweredy to the levelofthe-lowerendfof tube*- v 44; tolassure highly efficient. operation.

`The cover-'28'may be easily and-,quickly removed 'by releasing the thumb screws- 33- and swinging the clamping bars 3l over the edge ofV the trap.4 If partition IU and baille plates 34.' are made' removable thecleaningoperation isigreatlyy facilitatecl. Itaw-ill benoted that whiletube-,M is-ef: fectivertovent thetrap' intothe outlet` conduit 39 when necessary, normallyI the' fluid level will be above the lower endA off tube 44; thus? preyentirlg the entry-of sewer gases into the; trappr. escape of'fsuchgases therefrom when coven Z8isz-removed for cleaningl pur-poses..

It will. thus be seen that I- have provideday devicev `comprising al: closed receptaclel sealed: against'the escape-ufl gaseous andother fluids by a'exible connection; in.` the sewagev line, in .which waste Water,v directed thereinto is uniformly spreadwith a consequent retardedlrate of flow` to enable effective separation ofthe-grease; ain and other lighter-than-air. particles-to -thefupper -partfofthe receptacle: from which i. the: samefmay be-removedrwithlfacility, and incorporatingmeans to relieve-the pressure of gaseous accumulations in thelupper-part of the-receptacle on the uidby bypassing-saidgases intothe sewage disposal pipe, said-means,- al'so being effective as an anti-Siphon expedient to prevent fluids from being drawn fromthe receptacle.'below` a predetermined level,` thereby assuring asufficient fluid. volume within the receptaclefor efflcientoperation. Figs; -and-Grhavefshowma modiedform of'4 trap,-, embodying the. present4 invention. The body of the-trap issubstantially the same-as the Adevicefof Figs-. v 1-'4 including the: partition-f Ill ings 5U with respect to the adjacent side walls and the bottom of the trap are identical whereby the'inlet and outlet ttings about to be described more in detail, maybe connected to either of said openings. The edge of each opening"50 is recessed as at 5I to provide an annular bead 52 to one of which the flexible connection for an inlet pipe 53 is attached in the manner hereinabove described with reference to the embodiment as shown in Figs. l-4. An outlet fitting is connected to the opposite opening 5U, comprising a threaded pipe 54 having a flange 55 at one end of a diameter slightly less than that of bead 52 to permit the extension of the flanged end 55 of the pipe into the opening 50. The ilange provides a seat for a gasket 56 having a. pair of spaced annular flanges 51-51 engageable with opposite sides of bead 52. A clamping nut threaded on pipe 54 compresses the gasket to eiect the seal between the body of the trap and said pipe. To the outer end of pipe 54 an elbow 58 is threaded for the attachment of a vertically disposed short pipe section 59. A T-fitting 60 secured to the upper end of section 59 affords a lateral threaded outlet 6I which determines the fluid level within the trap chambers, and to which a sewer pipe (not shown) may be connected. A vent pipe 62 is secured in any conventional manner in the upper end of the T-tting to prevent siphoning of the trap. A strap encircles pipe section 59 and is secured to the adjacent end of the trap by a bolt 63, extending through a suitably located hole 64 in the end wall of the trap to reinforce the outlet tting. If the outlet and inlet ttings are attached in opposite openings 50, it will be understood that a plug (not shown) may be employed to close the hole 64 not used.

The cover 28 of the trap is secured on a ledge 21 by novel clamping means adapted to engage under each of a series of lugs 65 integral with the inner surface of the trap adjacent each corner slightly below the ledge 21. A screw 66 is threaded through cover 28- adjacent each lug 65. Wings 61 on upper end of each screw 66 facilitate manual turning of the latter inA a counterclockwise direction to swing a lateral extension 68 at the lower end of the screw under the adjacent lug 65.v coincidentally, extension 68 is raised by the threads on the shank of the screw so as to engage the underside of lug 65 and draw the cover tightly onto the ledge of the trap. The separation of the lighter-than-water constituents of the iluid introduced into the trap is effected in the same manner as in the embodiment of Figs. 1 4 regardless of the opening 50 to which the respective inlet and outlet fittings are connected.

It will be understood that the contour of the body of the trap may be varied to meet speciiic requirements. In Fig. 7 a trap is illustrated having the form, in plan, of an ellipse which is particularly adapted to be moulded from vitreous china. The lower portion of one end of the trap is projected as at 69 to provide two openings 10, identical in form, communicating with opposite trap chambers for connection of the inlet and outlet fittings hereinabove described, whereby the ilow through the trap may be in either direction, depending upon to which of the openings the respective inlet and outlet ttings are connected.

While I have illustrated and described but one embodiment of my invention, it will be apparent to those of skill in this art that numerous changes in size, design, shape and number of the various parts may be made, that additional baiiles may be provided which may vary in size and arrangement depending upon the capacity of the trapv and the grease content of the fluid passing from the ilxture being serviced, that any well-known means for removably securing and sealing the cover in place may be substituted for that shown, and that insofar as the function of the tube in preventing the siphoning of the trap and relieving pressure of gas accumulated therein is concerned, the tube 44 may be connected directly with the end wall of the trap adjacent the upper part of the latterall without departing from the spirit of my invention as defined in the appended claims.

What I claim and desire to secure by Letters Patent is:

l. In a trap, a basin comprising side walls and a bottom, a partition dividing the basin longitudinally to form a pair of trap chambers communicated with one another through an opening 'in the partition, a baille in each trap chamber extending between said partition and the opposed side walls respectively, and spaced from the bottom of the trap, and a dam in each trap chamber extending laterally from the partition and upwardly from the bottom of the trap, said dams being spaced from the side walls of the trap.

2. In a trap, a basin comprising side walls and a bottom, a partition dividing the trap into two trap chambers, said partition having an opening therein communicating said trap chambers with one another, one of said side walls having inlet and outlet openings therein closely adjacent the bottom of the trap, a baille within each trap chamber extending laterally from opposite sides of the partition, and spaced from the bottom of the trap, and a dam between the opening and the baille in one of said trap chambers extending upwardly from the bottom a distance slightly greater than the distance between the bottom of the trap and the lower edge of the last named baille.

3. In a trap, a basin comprising side walls and a bottom, a partition dividing said trap to form a pair of trap chambers, one of said walls having a pair of openings therein communicating with respective trap chambers, said partition having r an opening therein adjacent the bottom and the wall opposite to the wall in which said openings are located, said opening in the partition being ofgradually diminishing width toward its upper edge.

4. In a trap, a basin comprising walls and a bottom, a partition dividing a trap into two trap chambers, said partition having an opening therein adjacent the bottom, a baille plate transverse to said partition in each trap chamber and spaced from the bottom, a pair of dams supported on the bottom in each trap chamber, extending from opposite sides of the partition, said dams projecting upwardly a distance slightly greater than the distance between the bottom of said baille plates, and spaced from the adjacent transverse walls of the trap, an inlet and an outlet opening in one wall of the trap adjacent the bottom, opening into respective trap chambers. v 5. In a trap, a basin comprising side walls and a bottom, a cover plate, means td clamp said cover plate on said basin to seal the top of the latter, one of said walls having an inlet and an outlet opening adjacent the bottom thereof, an outlet conduit connected to said outlet opening extending upwardly exteriorly of said basin to adjacent the upper edge of the latter, said conduit having a cleanout opening at its upper end and a lateral outlet opening adjacent its upper end, means forming a channel communicatedwith the upper part of the basin and opening exteriorly of the basin laterally of and substantially at the same level as said cover plate, a separately-removable cap sealing said exterior opening in said channel, and a tubular member leading from said outlet conduit intermediate the lateral opening therein and the lower end thereof to said channel.

6. In a trap, a basin comprising side walls and a bottom, a cover plate, means to clamp said cover plate on said basin to seal the top of the latter, one of said walls having an inlet and an outlet opening adjacent the bottom thereof, an outlet conduit connected to said outlet opening extending upwardly exteriorly of said' basin to adjacent the upper edge of the latter, said conduit having a lateral outlet opening adjacent its upper end, means forming a channel communicated with the upper part of the basin and opening exteriorly of the basin laterally of and substantially at the same level as said cover plate, a separately-removable cap normally sealing said exterior opening in said channel, and Yal tubular member leading from said outlet conduit intermedi-ate the lateral opening therein and the lower end thereof to said channel.

7. In a trap, a basin having an inlet and an outlet opening therein, a vertical partition in said basin having an opening therein adjacent the bottom thereof, said opening being of lesser crossbers, and baffles disposed in each trap chamberarranged transversely to said partition to afford a sinuous passage adjacent the bottom of the basin for fluid moving from the inlet opening through the opening inthe partition to the outlet opening.

9. In a trap, -a basin comprising side Walls and a bottom, said basin having inlet and outlet openings, and means comprising a plurality of bailles disposed adjacent said bottom of said basin denng a passage for fluid from said inlet to said outlet openings, said passage being sinuous in a vertical plane to effect an undulating movement in iluid owing from said inlet to said outlet opening, respectively.

CHARLES ARNDT. 

